Rotational thrombectomy wire

ABSTRACT

A rotational thrombectomy wire for breaking up vascular thrombus or other obstructive material having a core having a proximal region and a distal region and being rotatable by a motor. The distal region has a smaller diameter than the proximal region. A cable is coupled to the distal region of the core and extends distally thereof. A torque tube is positioned over the cable and a coil is positioned over a distal portion of the cable. A distal portion of the cable has a non-linear configuration. A first covering material is positioned over the coil.

This application claims priority from provisional application Ser. No.61/431,169, filed Jan. 10, 2011, and is a continuation in part of Ser.No. 13/095,329, filed Apr. 27, 2011, which claims priority fromprovisional application Ser. No. 61/334,412, filed May 13, 2010 theentire contents each of these applications are incorporated herein byreference.

BACKGROUND

1. Technical Field

This application relates to a rotational thrombectomy wire for clearingthrombus from native vessels.

2. Background of Related Art

There have been various attempts to break up clots and other obstructingmaterial in grafts or native vessels. One approach is through injectionof thrombolytic agents such as urokinase or streptokinase. These agents,however, are expensive, require lengthy hospital procedures and createrisks of drug toxicity and bleeding complications as the clots arebroken.

Other approaches to breaking up clots involve mechanical thrombectomydevices. For example, U.S. Pat. No. 5,766,191 discloses a cage or basketcomposed of six memory wires that expand to press against the innerlumen to conform to the size and shape of the lumen. This multiple wiredevice is expensive and can be traumatic to the graft, possibly causingdamage, since as the basket rotates, the graft is contacted multipletimes by the spinning wires. Other risks associated with the basketinclude the possibility of catching onto the graft itself and tearingthe graft as well as catching and tearing the suture at the anastomoticsite. Additionally, the basket can become filled with a clot which wouldthen require time consuming withdrawal of the basket, cleaning thebasket and reinserting it into the lumen. This device could be traumaticif used in the vessel, could denude endothelium, create vessel spasmsand has the potential for basket and drive shaft fracture.

U.S. Pat. No. 6,090,118, incorporated herein by reference in itsentirety, discloses a wire rotated to create a standing wave to break-upor macerate thrombus. The single wire is less traumatic than theaforedescribed basket device since it minimizes contact with the graftwall while still effectively mechanically removing thrombotic material.

U.S. Pat. No. 7,037,316 discloses another example of a rotationalthrombectomy wire for breaking up clots in grafts. The thrombectomy wirehas a sinuous shape at its distal end and is contained within a sheathin a substantially straight non-deployed position. When the sheath isretracted, the distal portion of the wire is exposed to enable the wireto return to its non-linear sinuous configuration. The wire is composedof two stainless steel wires wound side by side with an elastomeric tipat the distalmost end. Actuation of the motor causes rotational movementof the wire, creating a wave pattern, to macerate thrombus. Thus, itprovides the additional advantages of increased reliability andconsistency in creating the wave pattern since the wave pattern createdby the standing wave of the '118 patent will depend more on therotational speed and the stiffness of the wire. Additionally, thesinuous configuration enables creation of a wave pattern at a lowerrotational speed.

Although the sinuous wire of the '316 patent is effective in properclinical use to macerate thrombus in dialysis grafts, it is not bestsuited for use in native vessels. U.S. Pat. No. 7,819,887, the entirecontents of which are incorporated herein by reference, discloses athrombectomy wire better suited for use in native vessels (and can alsobe used for deep vein thrombosis and pulmonary embolisms).

In neurovascular thrombectomy procedures, the thrombectomy wire needs tonavigate tortuous vessels. That is, the wire is inserted through femoralartery and then must navigate small and tortuous vessels as it isadvanced to the smaller cerebral arteries of the brain. Within thebrain, the carotid and vertebrobasilar arteries meet to form the circleof Willis. From this circle, other arteries, e.g., the anterior cerebralartery, the middle cerebral artery and the posterior cerebral artery,arise and travel to various parts of the brain. Clots formed in thesecerebral arteries can cause stroke and in certain instances death of thepatient.

Due to the size and curves of the vessels en route to the cerebralarteries from the femoral artery, as well as the size and structure ofcerebral arteries themselves, access is difficult. If the thrombectomydevice is too large then navigation through the small vessels, which canbe as small as 1 mm, would be difficult. Also, if the device is toostiff, then it can damage the vessel walls during insertion. On theother hand, if the device is too flexible, it will lack sufficientrigidity to be advanced around the vessel curves and can be caught inthe vessel. Consequently, it would be advantageous to provide athrombectomy device for breaking cerebral clots that strikes the optimalbalance of flexibility and stiffness, thus effectively having theinsertability of a tracking guidewire while enabling high speed rotationto effectively macerate clots without damaging vessels.

SUMMARY

The present invention advantageously provides in one aspect a rotationalthrombectomy wire for breaking up vascular thrombus or other obstructivematerial. The wire comprises a core having a proximal region and adistal region and being rotatable by a motor, the distal region having asmaller diameter than the proximal region. A cable is coupled to thedistal region of the core and extends distally thereof. A torque tube ispositioned over the cable and a coil is positioned over a distal portionof the cable. The distal portion of the cable has a non-linearconfiguration. A first covering material is positioned over the coil.

In some embodiments, a hypotube couples a distal end of the core to aproximal end of the cable. A second covering material can cover thetorque tube. A heat shrink can cover the first covering material. Insome embodiments, the second covering material overlies a portion of thecore and extends to a region proximal of the first covering material.

In some embodiments, the non-linear distal region of the cable issinuous in configuration. In other embodiments, the non-linear distalend of the cable is J-shaped in configuration.

In some embodiments, the wire is removably coupled at a proximal end toa motor drive shaft. The wire can be movable within a lumen of ahousing, the housing having a suction port extending therefrom andcommunicating with the lumen.

In another aspect, the present invention provides an assembly forbreaking up vascular thrombus or other obstructive material comprisingan introducer sheath having a lumen, a rotational thrombectomy wireslidable within the lumen of the introducer sheath, and a connectorhaving a distal portion connectable to the introducer sheath and aproximal portion connectable to a motor housing, the wire operablyconnectable to a motor positioned within the motor housing.

The wire can comprise a core having a distal region with a smallerdiameter than the proximal region. The wire can further include a cableextending distally of the core, a coil attached to a distal portion ofthe cable and a first covering material positioned over the coil. Insome embodiments, a portion of the cable assumes a non-linear shape whenexposed.

A housing having a first lumen can be provided, with the introducersheath connectable to the housing and insertable through the firstlumen. In some embodiments, the housing can include a suction arm havinga second lumen, with the second lumen configured to remove particlesremoved by rotation of the wire. The assembly can further include acatheter extending distally of the housing wherein exposure of the wirefrom the catheter enables a distal portion of the wire to assume anon-linear configuration. The assembly can further include a motorhousing.

In another aspect, the present invention provides a method for removingthrombus in a cerebral artery of a patient comprising the steps of:

introducing a guidewire and a first catheter into the femoral artery;

advancing the first catheter through the vascular system;

removing the guidewire;

providing a housing and a second catheter extending distally from thehousing;

providing an introducer sheath;

connecting the introducer sheath to the housing;

inserting a rotational thrombectomy wire through the introducer sheathand through the second catheter;

advancing the thrombectomy wire within the catheter to access thecerebral artery;

subsequently operably coupling a motor to the proximal end of thethrombectomy wire; and

activating the motor to rotate the thrombectomy wire to maceratethrombus in the cerebral artery.

In some embodiments, the step of advancing the thrombectomy wire to thecerebral artery includes the step of inserting the thrombectomy wireinto the circle of Willis. The method may further include the step ofproviding a connector tube and attaching a proximal end of the connectortube to a motor housing and a distal end of the connector tube to theintroducer sheath. The method may also include the step of providing avacuum to remove particles from the artery.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiment(s) of the present disclosure are described hereinwith reference to the drawings wherein:

FIG. 1 is a perspective view of a first embodiment of a thrombectomyapparatus of the present invention;

FIG. 2 is an exploded view of the proximal portion of the thrombectomyapparatus of FIG. 1;

FIG. 3 is a side view in partial cross-section of the apparatus of FIG.1 with the rotational wire contained within the introducer sheath;

FIG. 3A is longitudinal cross-sectional view taken along line 3A-3A ofFIG. 1;

FIG. 4 is a side view of the apparatus of FIG. 1 showing the rotationalwire in a non-linear position corresponding to a position exposed fromthe introducer sheath;

FIG. 4A is an enlarged view of the distal portion of one embodiment ofthe thrombectomy wire having a sinuous configuration;

FIG. 4B is an enlarged view of the distal portion of an alternateembodiment of the thrombectomy wire having a J-tip configuration;

FIG. 5 is a longitudinal cross-sectional view of the distal portion ofthe thrombectomy wire of the apparatus of FIG. 1;

FIG. 6 is an anatomical view showing select cerebral arteries;

FIG. 7 is a front anatomical view showing select cerebral arteries,including the circle of Willis;

FIG. 8 illustrates insertion of a guide catheter through the femoralartery and into the cerebral artery over a tracking guidewire;

FIG. 9 is a view similar to FIG. 8 illustrating withdrawal of thetracking guidewire;

FIG. 9A is a perspective view illustrating attachment of the RHV to theintroducer catheter;

FIG. 10 illustrates insertion of the introducer catheter of thethrombectomy apparatus through a guide catheter and into the circle ofWillis and insertion and attachment of the RHV to the introducercatheter;

FIG. 10A is a perspective view illustrating insertion of the introducersheath into the RHV;

FIG. 10B is a perspective view illustrating attachment of the connectortube to the introducer sheath;

FIG. 10C is a perspective view of another introducer catheter;

FIG. 10D is a side view showing attachment of the RHV and the introducercatheter of FIG. 10C;

FIG. 11 illustrates insertion of the thrombectomy wire of FIG. 1 intothe RHV and through the introducer catheter, and continued advancementof the thrombectomy wire of FIG. 1 from the introducer catheter so thedistal portion of the wire is positioned in the circle of Willis; and

FIG. 12 is a perspective view of an alternate embodiment of theapparatus.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Referring now in detail to the drawings where like reference numeralsidentify similar or like components throughout the several views, FIG. 1illustrates a first embodiment of the thrombectomy apparatus of thepresent invention.

The thrombectomy apparatus of FIG. 1 is designated generally byreference numeral 10. With reference to FIGS. 1 and 2, the apparatusincludes a motor housing 12, a rotational thrombectomy wire 30, arotating hemostatic valve (RHV) 40, an introducer sheath 60 and atelescoping tube or tubular connector 80. The RHV 40 is connectable toan introducer catheter 100 discussed below in conjunction with themethod of use (see e.g. FIG. 10). The introducer sheath 60 is insertableinto the RHV 40 to facilitate insertion of the thrombectomy wire 30through the RHV 40 and introducer catheter 100.

The thrombectomy apparatus or assembly 10 disclosed herein provides arotational thrombectomy wire as a separate unit from a catheter. Thatis, the thrombectomy wire 30 is provided as a separate unit insertablethrough the RHV 40. The RHV 40 has a distal end 52 connected to aproximal end of the introducer catheter 100 to access the surgical site.The introducer sheath 60 aids insertion of the thrombectomy wire intothe RHV 40 and through the introducer catheter, with the walls of theintroducer sheath 60 maintaining the non-linear distal end of the wire30 in a substantially straightened (substantially linear) configurationas it enters the RHV 40.

Additionally, the thrombectomy wire 30 of the present invention can beslid within the introducer sheath 60 and introducer catheter 100 priorto connection to the motor, if desired. This can aid introduction andmanipulation of the wire 30 since it is less cumbersome and of lighterweight than if the motor housing was attached during manipulation of thewire. However, it is also contemplated that the wire 30 could beattached to the motor housing 12 prior to insertion through theintroducer sheath 60, RHV 40 and the introducer catheter 100 and thusthe wire 30 would be slidable within the introducer sheath 60 (andintroducer catheter 100) with the motor housing 12 attached. Thus, themotor housing 12 can be attached to the wire at a desired time prior toor during the procedure.

Turning to the specific components of the thrombectomy apparatus 10, andwith reference to FIGS. 1-4, the motor housing 12, which also forms ahandle portion, has two identical housing halves 13 a, 13 b. A motor 14is seated within recess 14 a of housing half 13 a and the opposingrecess of housing half 13 b and has a motor drive shaft 15 extendingtherefrom. Tabs 15 b (FIG. 3) help secure the motor 14 within thehousing 12. A gear reducer (not shown) could optionally be provided toreduce by way of example the rotational speed of the motor 52 from15,000 rpm to 1500 rpm, 750 rpm, 150 rpm, etc. One or more batteries 16,such as a 3 Volt battery, is positioned in recess 17 a of housing half13 a and the opposing recess of housing half 13 b for powering the motor14. The battery(s) 16 can be contained within a compartment in thehousing 12 accessible by removing a battery door. The motor drive shaft15 connects to a proximal end of the thrombectomy wire 30 by variouscouplings, such as for example a snap fit wherein cap 31 of at theproximal end of wire 30 is frictionally fit over the motor drive shaft15. Various other types of connections are also contemplated. A printedcircuit board can also be provided within the housing 30 and isdesignated by reference numeral 18.

Motor housing 12 includes a distal tubular portion 22 having a tab inthe form of a ring 24 which fits within a groove in the tube connector80, best shown in FIG. 3 to connect the motor housing 12 to tubeconnector 80 described below.

Switch 19 extends though recess 21 in housing half 13 a and in acorresponding recess in housing half 13 b. A potentiometer (not shown)can optionally be wired to the motor to enable dialing the motor speedup or down to adjust the rotational speed of the thrombectomy wire 30 toadjust for various procedures and/or clot locations and sizes. In apreferred embodiment, the potentiometer is used as a two terminalvariable resistor, i.e. a rheostat, by not connecting the thirdterminal. In this manner, in the initial position, the motor speed is atthe desired minimum and rotation of a knob (or in alternate embodimentssliding of a knob) progressively increases the motor speed. Thus, theon/off switch 19 extending from the housing 12 is electrically connectedto the motor 15 to turn on the motor 15 to activate the apparatus, i.e.rotate the wire 30.

Turning to the other components illustrated in FIGS. 2-4, rotatinghemostatic valve (RHV) or housing 40 is connectable to an introducercatheter 100 (see FIG. 9A). A conventional introducer catheter can beutilized or alternatively a specially designed catheter for use with theapparatus of the present invention. As is standard, the RHV 40 isrotatable with respect to the catheter 100 to alter the orientation ofthe side arm 56.

Side arm 56 extends from the tubular portion 46 of RHV 40 and has a port57 for introduction of fluids and/or application of vacuum as describedbelow. Luer lock is provided at the distal end 52 of RHV 40 to connectto the introducer catheter 100 as internal threads 51 a of rotation knob51 threadingly engage external proximal threads of the introducercatheter 100. Tube extension 48 fits within the lumen of the introducercatheter 100 when attached. Washers 49 a, 49 b help to provide a sealagainst fluid flow.

Tubular portion 46 of RHV 40 includes a lumen 55 extending therethroughto slidably receive the tubular portion 62 of the introducer sheath 60.Proximal cap 58 at proximal end 54 has internal threads 59 tothreadingly attach to external proximal threads 47 of RHV 40 forattachment of the cap 58 to the RHV 40. Further, a crush ring 43 anddistal ring 44 are seated within the internal lumen 55 of the tubularportion 46. Thus, as cap 58 is tightened on RHV 40 by rotation, itcompresses rings 43 and 44 against the tubular portion 62 of introducersheath 60 extending therethrough to connect the introducer sheath 60 tothe RHV 40. A proximal seal 45 can also be provided. Flange 46 a on theproximal end 54 of RHV 40 interacts with lip 58 a of cap 58 to allowloosening of cap 58 to release introducer sheath 60 without cap 58detaching from RHV 40.

Side arm 56 of RHV 40 has a lumen 53 (FIG. 3A) in fluid communicationwith lumen 55 of tubular portion 46. Fluids such as imaging dye can beinjected through the arm 56, flowing through the lumens 53 and 55, i.e.through the space between the inner wall of lumen 55 and the outer wallof the introducer sheath 60, and then through the space between thethrombectomy wire 30 and the inner wall of the introducer catheter 100,exiting a distal opening 103 (FIG. 10) in the introducer catheter 100 toflow into the vessel. This imaging dye can be used to provide anindication that fluid flow has resumed in the vessel.

The side arm 56 can also be used for vacuum to suction particlesdetached from the vessel by the rotational wire 30. The particles wouldflow into the distal opening 103 of the introducer catheter 100 andthrough the space between the wire 30 and the inner wall of theintroducer catheter 100, continuing through lumen 55 and then exitingthrough lumen 53 and port 57 into a suction tube (not shown).

It should also be appreciated that the guide catheter 150 discussed inconjunction with the method of use below can also have a side arm forinjection of fluid (see e.g. side arm 152 of FIG. 8).

In the alternate embodiment of FIG. 12, the RHV ′ does not have a sidearm. In this embodiment, a guide catheter with a side arm can be usedfor injection and suction. Otherwise the components are identical to thecomponents of FIG. 1 and for convenience, the corresponding componentsare labeled with “prime” designations e.g., rotational knob 51′, cap58′, introducer sheath 60′, connector tube 80′ and locking cap 83′.

The tubular portion 62 of introducer sheath 60, as noted above, extendsthrough the lumen 55 of RHV 40 and terminates either within RHV 40 or ata proximal portion of the lumen of the introducer catheter 100. Thetubular portion 62 preferably has a stiffness greater than the stiffnessof the thrombectomy wire 30 to maintain the wire 30 in a straightenedposition during passage of wire 30 into the RHV 40 for subsequentpassage through the lumen of the introducer catheter 100 to the surgicalsite.

Proximal end 65 of introducer sheath 60 is attachable to connector tube80. Preferably, the enlarged proximal end 65 has a threaded flange 67 asshown in FIG. 3A to threadingly engage the internal threads 85 on thedistal cylindrical locking cap 83 at the distal end 82 of tubularconnector 80. A valve can be provided within the distal end 82 of theconnector tube 80 in addition or instead of a valve in a proximal end 65of the introducer sheath 60 to seal escape of fluid to improve thevacuum through the side arm 56.

Note the tube 80 and introducer sheath 60 can alternatively be providedas one unit, attached together and positioned over the thrombectomy wire30 as an attached unit. However, in alternative embodiments, the wire 30is inserted through the introducer sheath 60 and manipulated through theintroducer catheter 100 to the surgical site. Once positioned, theconnector tube 80 is then threadingly attached at the distal end 82 tothe introducer sheath 60 as noted above and at a proximal end 84 to themotor housing 12. In this version, the connector tube 80 can bepositioned over the wire 30 prior to insertion of the wire 30 throughintroducer sheath 60 or after insertion through the sheath 60. The wire30 can be packaged with the sheath 60 and the tube 80 positionedthereover, or packaged apart from the sheath 60 and tube 80.

Proximal end 84 of connector tube 80 is configured for attachment to themotor housing 12 by an external ring 24 on tip 22 of motor housing 12.Ring 24 is seated within an internal groove of connector tube 80, asshown in FIG. 3, to provide a snap fit. Other types of attachment arealso contemplated. The proximal end of the wire 30 is attached to thedrive shaft 15 of the motor 14. In one embodiment, end cap 31 of wire 30is snap fit within opening 15 a in motor shaft 15. Other ways to attachthe wire 30 and motor shaft 15 are also contemplated such as a bayonetmount for example.

As can be appreciated, by having a detachable motor housing 12,different handles with different motor speeds and/or different batteriescan be utilized by attachment to the wire 30. This can even be achievedduring the same surgical procedure.

In some embodiments, the housing can be detached, sterilized and reusedafter recharging of the battery or replacing the battery.

In some embodiments, as an alternative to direct connection to the motorshaft, the proximal end of wire 30, after insertion to the surgical siteor prior to insertion, can be attached at a proximal end to a couplertube which is connected to a gear reducer. The connection can be afriction fit, a magnetic coupling or a twist connect, e.g. a bayonetconnection, by way of example.

FIG. 5 illustrates one embodiment of the thrombectomy wire 30 of thepresent invention. The wire 30 has a distal coiled tip 91. In preferredembodiments, the distal coiled tip (and underlying cable) is angled withrespect to the longitudinal axis. FIG. 4A shows the wire of FIG. 5forming a sinuous shape. In FIG. 4B, an alternative embodiment of thewire is illustrated, wherein the wire 130 forms a J-tip which creates astanding wave upon rotation. In the J-tip configuration, due to theangle, when the wire is rotated by the motor at sufficient speed atleast one vibrational node is formed. Details of this creation of astanding wave are described in U.S. Pat. No. 6,090,118, the entirecontents of which are incorporated herein by reference.

In the embodiment of FIG. 4A, the wire 30 forms a substantially sinuousshape, resembling a sine curve. More specifically, wire 30 of FIG. 4Ahas a substantially linear portion extending through most of its length,from a proximal region, through an intermediate region, to distal region36. At the distal region 36, wire 30 has a sinuous shape in that asshown it has a first arcuate region 33 facing a first direction(upwardly as viewed in the orientation of FIG. 4A) and a second arcuateregion 35, spaced longitudinally from the first arcuate region 33,facing a second opposite direction (downwardly as viewed in theorientation of FIG. 4A). These arcuate regions 33, 35 form “peaks” tocontact vascular structure as the wire 30 rotates. This angled(non-linear) distal portion of wire 30 includes a coiled portion with acovering material to block the interstices of the coil as discussed inmore detail below. Note in a preferred embodiment, the amplitude of theproximal wave (at region 33) is smaller than the amplitude of the distalwave (at region 35), facilitating movement in and out of the catheter.

When the wire 30 is fully retracted within the introducer catheter 100(as in FIG. 3), the curved regions of the wire 30 are compressed so thedistal region 36 is contained in a substantially straight orsubstantially linear non-deployed configuration. When the introducercatheter 100 (attached to RHV 40) is retracted by proximal axialmovement (see the arrow of FIG. 4), or the wire 30 is advanced withrespect to the introducer catheter 100, or the wire 30 and catheter 100are both moved in the respective distal and proximal directions, thedistal region 36 of the wire 30 is exposed to enable the wire 30 toreturn to its non-linear substantially sinuous configuration shown inFIG. 4A (and FIG. 4) for rotation about its longitudinal axis within thelumen of the vessel.

Thus, as can be appreciated, the wire 30 is advanced within theintroducer catheter 100 which is attached at its proximal end to thedistal end of the RHV 40. When at the desired site, the wire 30 andintroducer catheter 100 are relatively moved to expose the wire 30 toassume its non-linear shape for motorized rotational movement to breakup thrombotic material on the vessel wall. If a J-tip wire, such as wire130 of FIG. 4, is utilized, the wire 130 can be rotated within theintroducer catheter 100 to re-orient the wire 130.

The flexible tubular portion 62 of the introducer sheath 60 canoptionally contain one or more braided wires embedded in the wall toincrease the stiffness. Such braided wires would preferably extend thelength of the sheath 60.

In an embodiment of the coiled tip being composed of shape memorymaterial, the memorized configuration is sinuous or s-shape as in FIG.4A. In the state within the introducer catheter 100, the wire is in asubstantially linear configuration. This state is used for deliveringthe wire to the surgical site. When the wire is exposed to warmer bodytemperature, the tip transforms to its austenitic state, assuming thes-shaped memorized configuration. Alternatively, the coiled tip of thewire can be compressed within the wall of the introducer catheter andwhen released, assumes its shape memorized non-linear shape. The coiledtip can alternatively be a radiopaque coil/polymer pre-shaped to an “S”.

Details of the wire 30 will now be described with reference to FIG. 5.These details are the same for wire 130, the only difference being thatinstead of the distal coiled tip of the wire being sinuous shaped in thedeployed position, the distal tip of the wire is in a J-configuration.Note it is also contemplated that in an alternate embodiment the distaltip of the wire can be substantially straight (substantially linear) inboth the covered and deployed (exposed) position. For convenience,details will be discussed with reference to wire 30.

Wire 30 has a core 32 having a proximal portion 34 (see FIG. 2) and adistal portion 37 (FIG. 5). Transition region 38 of core 32 is tapereddistally so that the diameter of the distal portion 37 of core 32 isless than the diameter of the proximal portion 34. A uniform diameterportion 37 a extends distal of tapered portion 37. The taper intransition region 38 can be formed by removing a coating, such as a PTFEcoating, placed over the core 32 and a grinding of the core 32. In oneembodiment, the core 32 is a solid material made of a nickel titaniumalloy, although other materials are also contemplated. The core 32 canalso be formed from a hypotube with a tapered body attached, e.g.welded, to the distal end of the hypotube.

The core 32 is connected to a cable 90. The cable 90 can be formed of aplurality of wires twisted together such as a 1×19 wire for example. Thetwisted wires can be surrounded by additional wires or a sheath. Thecore 32 is tapered to accommodate connection to cable 90. Hypotube 92 isplaced over the distalmost end of the core 32 (the uniform diameterportion 37 a) and the proximalmost end of the cable 90 and is attachedthereto by a number of methods, including but not limited to, laserwelding, soldering or crimping. The hypotube 92 thereby forms a couplerfor joining the core 32 and cable 90 as these components are positionedwithin the hypotube 92. The hypotube can have a diameter of about 0.010inches, although other dimensions are contemplated.

The cable 90 in one embodiment has a variable stiffness such that theproximal portion 94 is stiffer, e.g. has a tighter braid, than a distalportion 96 to increase the flexibility of the distal portion 96. Inother embodiments, the cable 90 is of uniform stiffness. The cable 90can be of substantially uniform diameter. Various covering materials,e.g. coating, jackets and/or shrink wraps, can be used as an alternativeor in addition to vary the stiffness of the cable 90.

A torque tube 97 is positioned over the cable 90. The torque tube 97extends distally from a tapered region of the core 32, terminating atthe distal coil 91. The torque tube 97 can be soldered at (proximal) end97 a to the core 32 and at a distal region 97 b (e.g. at a distal end)to the cable 90. The torque tube 97 can also be attached, e.g. solderedor laser welded, to a proximal end of the coil.

A polymer coating(s) and/or jacket(s) can be placed over the torque tube97 to cover the interstices in the cable 90 and provide a smoothsurface. In one embodiment, a PTFE shrink wrap tubing 98 is placed overthe torque tube 97 and over a portion of the core 32, preferablyextending over the tapered transition region 38 of core 32 to terminateat a proximal end adjacent the uniform diameter region of the core 32.At a distal end, the shrink wrap 98 terminates at the end where thetorque tube 97 terminates.

Coiled tip 91 is positioned over a distal portion of the cable 90, andpreferably over the distal tip. The coil 91 in one embodiment iscomposed of a soft and malleable material such as platinum and has auniform pitch and diameter. The distalmost tip of the cable 90 can havea laser welded ball to which the coil 91 is welded to enhance retentionof the coil 91 and cable 90. The coiled tip region has a substantiallysinuous configuration. In an alternate embodiment, the coiled tip regionhas a J-tip configuration, as shown for example in FIG. 4B. The coiledtip region can alternatively have a substantially linear configurationin the deployed/uncovered position. In each of these embodiments,preferably a covering such as a jacket, shrink wrap or coating coversthe coil 91. In a preferred embodiment, a nylon covering 99 is heatfused over the coil 91, to melt into the interstices. A heat shrinktubing 99 a, such as FEP, in some embodiments, is placed over the heatfused nylon coating. The covering 99, and heat shrink tubing 99 a,terminate adjacent a distal end of the torque tube 97 and adjacent adistal end of the shrink wrap 98.

By way of example only, the components of wire 30 can have theapproximate dimensions set forth in the table below. It should beunderstood that these dimensions are being provided by way of example asother dimensions are also contemplated. These are also approximatevalues.

APPROXIMATE APPROXIMATE COMPONENT OUTER DIAMETER LENGTH Core 32(proximal non .016 inches 139.5 cm tapered portion) Core tapered portion.016 inches to .0095 inches 4.35 inches Distal coil 91 .016 inches 3.0inches Torque tube 97 .013 inches 8.0 inches Shrink tube 98 .014 inches10.35 inches Cable 90 .010 inches 8.2 inches

The covering material, e.g. coating, jackets, and or shrink wraps, helpsto prevent bending or knotting of the wire which could otherwise occurin native vessels. The covering also increases the torsional strength ofthe wire and also strengthens the wire to accommodate spasms occurringin the vessel. The coating also blocks the interstices of the coil 91 toprovide a less abrasive surface. The various coating and/or jacketsand/or shrink wrap can be made of PET, Teflon, Pebax, polyurethane orother polymeric materials. The material helps to prevent the nativevessel from being caught in the coil 90 and reduces vessel spasms.

The use of the thrombectomy apparatus 10 will now be described. The use,by way of example is shown and described with respect to the embodimentof FIG. 1 with the sinuous tip wire of FIG. 4, it being understood thatthe wire embodiment of FIG. 4B would be utilized in a similar manner.

An access sheath (not shown) is inserted into the vessel and then aguidewire e.g. 0.035 or 0.038 inches in diameter, and a guide catheter150 are inserted through the sheath and advanced through thevasculature. The guidewire is removed and a smaller diameter guidewireG, e.g. 0.014 inch diameter, and the introducer catheter 100 areinserted through the guide catheter 150 and access sheath with theguidewire G in the femoral artery F and located via imaging. Theintroducer catheter 100 is advanced to the desired site through thevascular system into the cerebral arteries A, for example through theCircle of Willis C (see FIGS. 6, 7 and 8). Once at the site, theguidewire G is withdrawn as shown in FIG. 9. Note the introducercatheter 100 is preferably inserted with the RHV 40 attached. That is,the tubular portion 46 of the RHV 40 is inserted through the introducercatheter 100 (see FIG. 10) and attached thereto by rotation of cap 51 asshown in FIG. 9A. In the alternate embodiment of FIGS. 10C and 10D, RHV40 is attached to thread 124 of the winged luer fitting of introducercatheter 120 by rotation of cap 51 and/or winged handle 122.

Note in an alternate embodiment, instead of the RHV 40 attached prior tointroduction of the introducer catheter 100 through the guide catheter150, it can be attached after introduction of catheter 100 through guidecatheter 150.

The introducer sheath 60 is inserted through the RHV 40, and attached tothe RHV 40 by rotation of cap 58 as shown in FIG. 10A. The thrombectomywire 30 is inserted through the lumen of the introducer sheath 60,through the lumen of the RHV 40 and into the lumen of the introducercatheter 100. The introducer catheter 100 extends from the guidecatheter 150 as shown in FIG. 10, but the wire 30 remains inside theintroducer catheter 100. The distal end of the wire 30 is then exposedfrom the introducer catheter 100 at the target surgical site by relativemovement of the wire 30 and introducer sheath 100. Note the wire 30 canbe attached to the motor drive shaft 15 at this point or can be attachedbefore exposed or at any other time in the procedure such as prior toinsertion of the wire 30 through the introducer sheath 60. Attachment isachieved by connection of the connector tube 80 to the introducer sheath60 (see FIG. 10B) and attachment of the proximal end of the connector 80to the motor housing 12. The wire 30 extends through the connector tubeand attachment of the wire 30 (which extends through connector 80) tothe motor drive shaft 15. As noted above, alternatively, the connectortube 80 can be connected to the introducer sheath 60 prior to attachmentto the motor housing 12, or alternatively connected after the wire 30 isat the surgical site and exposed from the introducer sheath.

With the wire 30 exposed from the introducer catheter 100, switch 19 onhousing 12 is actuated to turn on the motor 14 thereby causing wire 30to rotate about its longitudinal axis to break up/macerate thrombus.

The macerated particles can be removed by suction through side arm 56 ofRHV 40 as the particles travel in the space between wire 30 andintroducer catheter 100 and RHV 40. The introducer catheter 100 canoptionally have a side port(s) and/or the guide catheter 150 canoptionally have a side port(s) such as side port 152 for aspirating thesmall macerated particles in addition to or alternative to side arm 56of RHV 40.

The delivery (access) sheath or delivery catheter 100 can include aballoon (not shown) to block blood flow and allow aspiration in theblocked space.

While the above description contains many specifics, those specificsshould not be construed as limitations on the scope of the disclosure,but merely as exemplifications of preferred embodiments thereof. Thoseskilled in the art will envision many other possible variations that arewithin the scope and spirit of the disclosure as defined by the claimsappended hereto.

1. A rotational thrombectomy wire for breaking up vascular thrombus orother obstructive material, the thrombectomy wire comprising a corehaving a proximal region and a distal region and being rotatable by amotor, the distal region having a smaller diameter than the proximalregion, a cable coupled to the distal region of the core and extendingdistally thereof, a torque tube positioned over the cable, a coilpositioned over a distal portion of the cable, the distal portion of thecable has a non-linear configuration, and a first covering materialpositioned over the coil.
 2. The thrombectomy wire of claim 1, furthercomprising a hypotube coupling the distal region of the core to theproximal region of the cable.
 3. The thrombectomy wire of claim 1,wherein a second covering material covers the torque tube.
 4. Thethrombectomy wire of claim 3, further comprising a heat shrink coveringthe first covering material.
 5. The thrombectomy wire of claim 1,further comprising a second covering material overlying a portion of thecore and extending over the torque tube to a region proximal of thefirst covering material.
 6. The thrombectomy wire of claim 1, whereinthe non-linear distal portion of the cable is sinuous in configuration.7. The thrombectomy wire of claim 6, wherein the sinuous configurationhas a first amplitude and a second amplitude distal of the firstamplitude, the second amplitude being greater than the first amplitude.8. The thrombectomy wire of claim 1, wherein the non-linear distalportion of the cable is J-shaped in configuration.
 9. The thrombectomywire of claim 1, wherein the wire is removably coupled at a proximal endto a motor drive shaft.
 10. The thrombectomy wire of claim 1, whereinthe wire is movable within a lumen of a housing, the housing having asuction port extending therefrom and communicating with the lumen. 11.An assembly for breaking up vascular thrombus or other obstructivematerial, the assembly comprising: an introducer sheath having a lumen;a rotational thrombectomy wire slidable within the lumen of theintroducer sheath; and a connector having a distal portion and aproximal portion, the distal portion connectable to the introducersheath and the proximal portion connectable to a motor housing, the wireoperably connectable to a motor positioned within the motor housing. 12.The assembly of claim 11, wherein the wire comprises a core having aproximal region and a distal region, the distal region having a smallerdiameter than the proximal region, and the wire further includes a cableextending distally of the core, a coil attached to a distal portion ofthe cable and a first covering material positioned over the coil. 13.The assembly of claim 11, further comprising a housing having a firstlumen, the introducer sheath connectable to the housing, and insertablethrough the first lumen.
 14. The assembly of claim 13, wherein thehousing includes a suction arm having a second lumen, and the secondlumen configured to remove particles removed by rotation of the wire.15. The assembly of claim 11, further comprising a catheter extendingdistally of the housing, wherein exposure of the wire from the catheterenables a distal portion of the wire to assume a non-linearconfiguration.
 16. The apparatus of claim 12, wherein the distal portionof the cable and the coil assume a non-linear configuration when exposedfrom a catheter.
 17. A method for removing thrombus in a cerebral arteryof a patient comprising: introducing a guidewire and a first catheterinto the femoral artery; advancing the first catheter through thevascular system; removing the guidewire; providing a housing and asecond catheter extending distally from the housing; providing anintroducer sheath; inserting a rotational thrombectomy wire through theintroducer sheath and through the second catheter; connecting theintroducer sheath to the housing; advancing the thrombectomy wire withinthe second catheter to access the cerebral artery; subsequently operablycoupling a motor to the proximal end of the thrombectomy wire; andactivating the motor to rotate the thrombectomy wire to maceratethrombus in the cerebral artery.
 18. The method of claim 17, wherein thestep of advancing the thrombectomy wire to access the cerebral arteryincludes the step of inserting the thrombectomy wire into the circle ofWillis.
 19. The method of claim 17, further comprising the step ofproviding a connector tube and attaching a proximal end of the connectortube to a motor housing and a distal end of the connector tube to theintroducer sheath.
 20. The method of claim 17, further comprising thestep of providing a vacuum to remove macerated particles from theartery.